# US 2021/0278315 A1 · Method for diagnosing wheel bearing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0278315 A1 - Document ID: US20210278315A1 - Status: Published application - Kind: A1 - Application number: 17/190,959 - Filed: 2021-03-03 - Published: 2021-09-09 - Earliest claimed: 2020-03-03 - Assignees: ILJIN GLOBAL Co.,Ltd - Applicants: ILJIN Global Co.,Ltd - Inventors: Jong Keun LIM - Web page: https://patentgrep.com/patent/US20210278315A1 ## CPC - G01M 13/045: Acoustic or vibration analysis - G01M 17/013: Wheels - G01P 7/00: Measuring speed by integrating acceleration (measuring travelled distance by double integration of acceleration G01C21/16) - G01P 15/00: Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract There is provided a method for diagnosing the presence of failure or abnormal operation of a wheel bearing. The method includes detecting acceleration information by an acceleration sensor mounted to a rotational central axis of the wheel bearing or at a position radially spaced apart from the rotational central axis and configured to rotate together with the wheel bearing; calculating speed information based on the acceleration information detected by the acceleration sensor; and diagnosing the wheel bearing based on the acceleration information detected by the acceleration sensor and the speed information calculated from the acceleration information. In the acceleration detection step, the acceleration sensor collects the acceleration information in at least one of a first direction extending radially from the rotational central axis of the wheel bearing and a second direction perpendicular to the first direction on a plane perpendicular to the rotational central axis of the wheel bearing. ## Claims ### Claim 1 A method for diagnosing the presence of failure or abnormal operation of a wheel bearing, the method comprising: an acceleration detection step of detecting acceleration information by an acceleration sensor mounted to a rotational central axis of the wheel bearing or at a position radially spaced apart from the rotational central axis and configured to rotate together with the wheel bearing; a speed calculation step of calculating speed information based on the acceleration information detected by the acceleration sensor; and a diagnosis step of diagnosing the wheel bearing based on the acceleration information detected by the acceleration sensor and the speed information calculated from the acceleration information, wherein in the acceleration detection step, the acceleration sensor is configured to collect the acceleration information in at least one of a first direction extending radially from the rotational central axis of the wheel bearing and a second direction perpendicular to the first direction on a plane perpendicular to the rotational central axis of the wheel bearing. ### Claim 2 (depends on 1) The method of claim 1, wherein the acceleration sensor outputs the acceleration information in the at least one of the first direction and the second direction as a sinusoidal signal according to the rotation of the wheel bearing. ### Claim 3 (depends on 2) The method of claim 2, wherein the speed information calculated based on the acceleration information detected by the acceleration sensor is calculated in consideration of a time taken to form one-cycle of the sinusoidal signal outputted from the acceleration sensor. ### Claim 4 (depends on 3) The method of claim 3, further comprising: a signal separation step of separating a signal of the acceleration information into a base signal and a vibration signal between the acceleration detection step and the speed calculation step. ### Claim 5 (depends on 4) The method of claim 4, wherein in the speed calculation step, the speed information is calculated based on the base signal. ### Claim 6 (depends on 5) The method of claim 5, wherein in the diagnosis step, the diagnosis of the wheel bearing is performed based on the vibration signal. ### Claim 7 (depends on 6) The method of claim 6, wherein the diagnosis step is configured to determine that the failure or abnormal operation of the wheel bearing is present when a frequency band where a peak signal is generated in the vibration signal coincides with a defect frequency band calculated from the base signal. ### Claim 8 (depends on 7) The method of claim 7, further comprising: a warning step of displaying the diagnosis result to the outside when it is determined that the failure or abnormal operation of the wheel bearing is present in the diagnosis step. ### Claim 9 (depends on 1) The method of claim 1, wherein the acceleration sensor is configured to be detachably mounted to one side of a wheel mounted to the wheel bearing so as to detect the acceleration information.